JP2000341175A - Video transmitter and monitor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video transmitter that continues transmission of video image information, even when a fault of a transmission line occurs such as a broken cable due to earthquake or installation work or the like, in a system that transmits video information by using the transmission line employing an optical fiber cable or a metallic cable or the like. SOLUTION: A monitor terminal(TM) 10 transmits a video signal obtained by an image pickup section (VC) 11 to a central supervisory unit(CS) 20 via a leased transmission line 30, when the leased transmission line 30 is normal. Furthermore, the terminal 10 receives a line check signal sent from the central supervisory unit(CS) 20 via the leased transmission line 30, to always check the abnormity of the leased transmission line 30 on the basis of the line check signal. When the terminal 10 detects a fault on the leased transmission line 30, the terminal 10 transmits the video signal obtained from the image pickup section (VC) 11, while selecting radio transmission instead of the optical transmission by the leased transmission line 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for transmitting video information using a transmission line using an optical fiber cable, a metal cable, or the like.
The present invention relates to a video transmission device suitable for application to an ision system or the like.

[0002] The present invention also relates to a surveillance camera device having a video transmission function, which is suitable for use in a system for remotely monitoring roads, rivers, various facilities, facilities, and the like.

[0003] The present invention also relates to a surveillance system in which video information obtained by a plurality of surveillance terminals provided with surveillance cameras is respectively transmitted to a central surveillance device via an optical fiber cable and remotely monitored by the surveillance device.

[0004]

2. Description of the Related Art Conventionally, in a CCTV system having an image transmission function of an ITV camera device, each camera device transmits an image via a dedicated transmission path using an optical fiber cable or a metal cable. Therefore, for example, if a cable constituting a transmission path is cut due to an earthquake, construction, or the like, and a transmission path abnormality occurs, there arises a problem that the video transmission is subsequently cut off due to the occurrence of the failure.

[0005]

As described above, in a conventional system having a video transmission function of a camera device, each camera device is connected to a dedicated transmission line using an optical fiber cable or a metal cable. Therefore, if the cable that constitutes the transmission path is cut due to, for example, an earthquake or construction, and a transmission path abnormality occurs, the video transmission will be cut off after that due to the failure. was there.

The present invention has been made in view of the above circumstances,
In systems that transmit video information using transmission lines that use optical fiber cables, metal cables, etc., video transmission is continued even if a transmission line abnormality such as cable disconnection due to an earthquake or construction occurs. It is an object of the present invention to provide a video transmission device capable of performing the above.

Further, the present invention relates to a monitoring system for transmitting video information obtained by a plurality of monitoring terminals having a monitoring camera to a central monitoring device via an optical fiber cable, and remotely monitoring by the monitoring device. It is another object of the present invention to provide a surveillance system capable of continuing video transmission and continuing intended surveillance work even when a transmission path abnormality such as a cable disconnection due to an earthquake or construction occurs.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a video transmission apparatus for transmitting a video, such as an ITV camera, which detects a video to be transmitted when an abnormality is detected in a transmission path provided for the original video transmission. Is encoded and transmitted using a spare transmission path, so that video transmission is continued.

That is, the present invention uses, for example, a transmission line using an optical fiber cable or a metal cable, and
In a video transmission apparatus for transmitting video information obtained by a TV camera, encoding means for encoding the video information, line abnormality detection means for detecting a line abnormality on the transmission line, and line abnormality detection means And a spare transmission unit for transmitting the video information encoded by the encoding unit when a line abnormality is detected.

The present invention also relates to a monitoring camera device applied to, for example, a CCTV system and the like.
A camera, a first transmission unit that transmits a video signal obtained from the camera to a predetermined point, a line abnormality detection unit that detects a line abnormality of the transmission unit, and a line abnormality detected by the line abnormality detection unit. A second transmission means for encoding a video signal obtained from the camera when detected and transmitting the encoded video signal to the point.

The present invention also relates to a surveillance camera device applied to, for example, a CCTV system or the like, and a surveillance camera and an optical transmission path for transmitting a video signal of a subject photographed by the camera to a predetermined point. Encoding processing means for encoding a video signal of a subject photographed by a camera, line abnormality detecting means for detecting a line abnormality in the optical transmission path, and when the line abnormality is detected by the line abnormality detecting means, Wireless transmission means for wirelessly transmitting the video signal encoded by the encoding processing means to the predetermined point by using a carrier wave of a predetermined frequency.

According to the present invention, there is provided a surveillance system for transmitting video information obtained by a plurality of surveillance terminals having a surveillance camera to a central surveillance device via an optical cable and remotely monitoring the surveillance device. In the monitoring terminal, means for detecting a line abnormality on the transmission line by the optical cable, means for encoding video information obtained by the camera when the line abnormality is detected by the means, and encoding by the means Means for wirelessly transmitting video information by a carrier wave of a predetermined frequency, wherein the monitoring device receives the video information transmitted from the monitoring terminal, and decodes the video information received by the monitoring device. Means for displaying the video information decoded by the means on a monitor. At this time, in the case of a system configuration in which a plurality of monitoring terminals transmit video signals using carrier waves in the same frequency band, the monitoring device specifies the monitoring terminal based on identification information included in received data. Further, in the case of a system configuration in which a plurality of monitoring terminals transmit video signals using carrier waves in different frequency bands, a plurality of reception units having a fixed reception frequency corresponding to a frequency assigned to each monitoring terminal, or on a transmission path. And a frequency-variable receiving unit that tunes to the frequency assigned to the monitoring terminal whose video transmission has been interrupted.

[0013] With the above-mentioned configuration having an automatic switching function of video transmission, video transmission can be continued even when a transmission path abnormality such as a cable cut due to an earthquake or construction occurs, and particularly in a disaster. It is possible to eliminate a system failure that sometimes interrupts video transmission.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention. Here, a plurality of monitoring terminals (TM) use optical fiber cables for a central monitoring device (CS) provided at a monitoring center. Only one monitoring terminal (TM) is shown, taking a monitoring system connected via a dedicated transmission line as an example.

In FIG. 1, reference numeral 10 denotes a monitoring terminal (TM) provided with an ITV camera for monitoring, and each of a plurality of predetermined points to be monitored, for example, roads, rivers, railway tracks, tunnels, etc. It is installed at each monitoring point.

Reference numeral 20 denotes each of the monitoring terminals (TM) 10, 1
0,... Are central monitoring devices (CS) provided at the monitoring center connected via dedicated transmission lines, and take in video signals transmitted from the monitoring terminals (TM) 10, 10,. Display on a monitor to enable remote monitoring by an observer.

Reference numeral 30 denotes each of the monitoring terminals (TM) 10, 1
0,..., The central monitoring device (C
S) This is a dedicated transmission line provided for video transmission with the device 20, and is configured using an optical fiber cable here.

Reference numerals 11 to 18 denote monitoring terminals (TM), respectively.
10 is a constituent element, 11 is an imaging unit (VC) using an ITV camera, 12 is a video switching unit (VSW) that switches the sending end of the video signal obtained by the imaging unit (VC) 11,
13 is an E / O converter for converting an electric signal into an optical signal;
Is an optical multiplexing / demultiplexing unit (O / O) that combines / demultiplexes optical signals having different wavelengths.
BF), 15 is an O / E converter for converting an optical signal into an electric signal, 16 is a line abnormality detector (DR-DET) for detecting a line abnormality of the dedicated transmission line 30, and 17 is a video for encoding a video signal. An encoding unit (ENC) 18 is a video encoding unit (EN
C) A wireless transmission signal transmitting unit (TX) that modulates the video signal encoded in 17 into a high-frequency signal of a predetermined frequency and transmits and outputs the signal from an antenna (antenna).

In the monitoring terminal (TM) 10, the video signal output from the imaging unit (VC) 11 is input to the video switching unit (VSW) 12. Video switching unit (VSW) 1
2 transmits a video signal input from the imaging unit (VC) 11 to the first video transmission terminal (a) when no abnormality detection signal is output from the line abnormality detection unit (DR-DET) 16 and detects a line abnormality. When the abnormality detection signal is output from the unit (DR-DET) 16, the video signal input from the imaging unit (VC) 11 is transmitted to the second video transmission terminal (b).

The video signal output from the first video transmission terminal (a) of the video switching unit (VSW) 12 is transmitted to an E / O conversion unit 13. The E / O converter 13 converts the input video signal into an optical signal and sends it to an optical multiplexer / demultiplexer (OBF) 14. The optical multiplexing / demultiplexing unit (OBF) 14 transmits the video signal converted into the input optical signal to the dedicated transmission line 30 as an optical signal having the wavelength f1.

Further, the optical multiplexing / demultiplexing unit (OBF) 14 is provided with an optical signal of wavelength f2 (converted into an optical signal) transmitted from the central monitoring unit (CS) 20 provided at the monitoring center onto the dedicated transmission line 30. Input the signal for line check)
It is sent to the O / E converter 15. The O / E conversion unit 15 converts the input optical signal into an electric signal, and converts the converted line check signal into a line abnormality detection unit (DR-DET) 16.
To send to. The line abnormality detector (DR-DET) 16
Dedicated transmission path 30 based on the input line check signal
It is determined whether or not the upper line is functioning normally, and when a line abnormality is detected, the video switching unit (VS) is detected by the detection signal.
W) 12 is controlled to be switched, and the video signal input from the imaging section (VC) 11 is sent to the second sending end (b) instead of the first sending end (a).

The video signal output from the second video transmission terminal (b) of the video switching unit (VSW) 12 is input to a video encoding unit (ENC) 17. Video encoding unit (ENC)
Reference numeral 17 compresses the input video signal by encoding, and then sends it to a wireless transmission signal transmission unit (TX) 18. The wireless transmission signal transmission unit (TX) 18 converts the input coded video signal into a high-frequency signal using a carrier of a predetermined frequency, and transmits and outputs the signal as a wireless transmission signal from an antenna (antenna).

Numerals 21 to 28 are constituent elements of a central monitoring device (CS) 20 provided at the monitoring center, and 21 is an optical multiplexing / demultiplexing unit (OBF) for combining / demultiplexing optical signals having different wavelengths. Reference numeral 22 denotes an O / E converter for converting an optical signal into an electric signal, and reference numerals 23 and 28 denote a monitor display (MO).
N) and 24 are line check signal generators for generating line check signals, 25 is an E / O converter for converting electric signals into optical signals, and 26 is each of the monitoring terminals (TM) 10, 1
The radio transmission signal receiving unit (RX) for receiving the radio transmission signal transmitted from 0,..., And the video decoding unit (DEC) 27 for decoding the coded video signal after reception.

In the central monitoring device (CS) 20,
The optical multiplexing / demultiplexing unit (OBF) 21 inputs the optical signal of the wavelength f1 transmitted from the monitoring terminal (TM) 10 onto the dedicated transmission line 30, demultiplexes the signal, and transmits the signal to the O / E conversion unit 22. The O / E converter 22 converts the input optical signal of the wavelength f1 into an electric signal, and sends the video signal to a monitor display (MON) 23. The monitor display unit (MON) 23 displays and outputs a video for monitoring according to the input video signal on a display screen in a predetermined display form (for example, a plurality of monitoring terminals (TM) 10, 1).
0,... Are simultaneously displayed on a multi-screen, or are switched and displayed in units of a fixed time).

The line check signal generator 24 generates a continuous (or constant period) line check signal.
It is sent to the E / O converter 25. The E / O converter 25 converts the input line check signal into an optical signal and sends it to the optical multiplexer / demultiplexer (OBF) 21. Optical multiplexer / demultiplexer (OBF) 2
1 transmits the line check signal converted into the optical signal input from the E / O converter 25 to the dedicated transmission line 30 as an optical signal of the wavelength f2.

A radio transmission signal receiving section (RX) 26
Receives a wireless transmission signal transmitted from each of the monitoring terminals (TM) 10, 10,..., Demodulates the wireless transmission signal, and converts an encoded video signal into a video decoding unit (DE).
C) Send to 27. The video decoding unit (DEC) 27 decodes the input coded video signal and decodes it into the monitor display unit (M
ON) 28. The monitor display unit (MON) 28 displays and outputs a monitoring image according to the input image signal on a display screen in a predetermined display form.

Here, the operation of the first embodiment shown in FIG. 1 will be described.

The monitoring terminals (TM) 10, 10,... Transmit the monitoring video signal obtained by the imaging unit (VC) 11 during the normal operation when the dedicated transmission line 30 is in a normal state.
Central monitoring device (C
S) Send to 20. Further, via the dedicated transmission path 30,
A line check signal transmitted from a central monitoring device (CS) 20 provided at a monitoring center is input, and the presence or absence of a line abnormality on the dedicated transmission line 30 is constantly checked based on the signal.

In the line check using the line check signal, if a line abnormality on the dedicated transmission line 30 is detected, the video signal obtained by the image pickup unit (VC) 11 is thereafter converted into an optical signal by the dedicated transmission line 30. Switching from transmission to wireless transmission.

That is, in the monitoring terminal (TM) 10, the imaging unit (VC) 11 captures an image of the monitoring target and sends the video signal to the input terminal of the video switching unit (VSW) 12.

At this time, when the abnormality detection signal is not output from the line abnormality detection unit (DR-DET) 16, the image switching unit (VSW) 12 converts the image signal input from the imaging unit (VC) 11 into the first image. The video signal input from the imaging unit (VC) 11 is transmitted to the transmission terminal (a), and when the abnormality detection signal is output from the line abnormality detection unit (DR-DET) 16, the second video transmission terminal ( b).

Therefore, when there is no line abnormality in the dedicated transmission line 30, the video signal obtained by the imaging unit (VC) 11 is output from the first video transmission terminal (a) of the video switching unit (VSW) 12.

The video signal output from the first video transmitting end (a) of the video switching section (VSW) 12 is converted into an optical signal via an E / O conversion section 13 and then converted to an optical multiplexing / demultiplexing section ( OB
F) The signals are combined at 14 and sent out onto the dedicated transmission line 30 as an optical signal of the wavelength f1.

Further, the optical multiplexing / demultiplexing unit (OBF) 14 is provided with an optical signal of wavelength f2 (converted into an optical signal) transmitted from the central monitoring unit (CS) 20 provided at the monitoring center onto the dedicated transmission line 30. Input the signal for line check)
A line abnormality detector (DR-DE) via the O / E converter 15
T) 16.

The line abnormality detector (DR-DET) 16
Dedicated transmission path 30 based on the input line check signal
It is determined whether or not the upper line is functioning normally, and when a line abnormality is detected, the video switching unit (VS) is detected by the detection signal.
W) 12 is controlled to be switched, and the video signal input from the imaging section (VC) 11 is sent to the second sending end (b) instead of the first sending end (a).

The video signal output from the second video transmission terminal (b) of the video switching unit (VSW) 12 is input to a video encoding unit (ENC) 17. Video encoding unit (ENC)
Reference numeral 17 compresses the input video signal by encoding, and then sends it to a wireless transmission signal transmission unit (TX) 18. The wireless transmission signal transmission unit (TX) 18 converts the input coded video signal into a high-frequency signal using a carrier of a predetermined frequency, and transmits and outputs the signal as a wireless transmission signal from an antenna (antenna).

On the other hand, in the central monitoring device (CS) 20 provided in the monitoring center, the optical signal of the wavelength f1 transmitted from the monitoring terminal (TM) 10 is transmitted via the dedicated transmission line 30 to the optical multiplexing / demultiplexing unit (CS). OBF) after being input to 21 and demultiplexed,
The signal is converted into an electric signal by the / E conversion unit 22, and the video signal is transmitted to the monitor display unit (MON) 23 and displayed on a display screen in a predetermined display form. For example, respective images received from a plurality of monitoring terminals (TM) 10, 10,... Are simultaneously displayed on a multi-screen. Or a plurality of monitoring terminals (TM) 1
Each video received from 0, 10,... Is switched and displayed in units of a fixed time.

After the line check signal generated by the line check signal generator 24 is converted into an optical signal by the E / O converter 25, the signal is processed by the optical multiplexing / demultiplexing unit (OBF) 21 to obtain a wavelength. The signal is transmitted to the dedicated transmission line 30 as an optical signal of f2.

When a radio transmission signal transmitted from each of the monitoring terminals (TM) 10, 10,... Is received by the radio transmission signal receiving unit (RX) 26 at the time of a line abnormality, the radio transmission signal Is demodulated as a coded video signal and further decoded by a video decoding unit (DEC) 27, sent to a monitor display unit (MON) 28, and displayed on a display screen in a predetermined display form. .

By providing the above-mentioned automatic switching function of the video transmission, the video transmission can be continued even when a transmission line abnormality such as a cable disconnection due to an earthquake, construction, etc. occurs. Therefore, a system failure in which video transmission is interrupted can be eliminated.

Next, a second embodiment of the present invention will be described with reference to FIG. Here, the same portions as those in the first embodiment shown in FIG. 1 described above are denoted by the same reference numerals, and description thereof will be omitted.

The difference between the second embodiment shown in FIG. 2 and the first embodiment is that the monitoring terminal (TM) 1
At 0, the wireless transmission signal transmission unit (TX) 18 is activated by an abnormality detection signal of the line abnormality detection unit (DR-DET) 16. Further, in the central monitoring device (CS) 20 provided in the monitoring center, the video of each terminal when the line is normal and when the line is abnormal is displayed and output on a common monitor display unit (MON) 23.

The operation of the second embodiment shown in FIG. 2 will now be described.

The monitoring terminals (TM) 10, 10,... Transmit the monitoring video signal obtained by the imaging unit (VC) 11 during the normal operation when the dedicated transmission line 30 is in a normal state.
Central monitoring device (C
S) Send to 20. Further, via the dedicated transmission path 30,
A line check signal transmitted from a central monitoring device (CS) 20 provided at a monitoring center is input, and the presence or absence of a line abnormality on the dedicated transmission line 30 is constantly checked based on the signal.

In the line check using the line check signal, if a line abnormality on the dedicated transmission line 30 is detected, the radio transmission signal transmission unit (T
X) 18 is activated, and thereafter, the video signal obtained by the image pickup unit (VC) 11 is transmitted by switching from optical transmission to wireless transmission through the dedicated transmission path 30.

That is, in the monitoring terminal (TM) 10, the imaging unit (VC) 11 captures an image of a monitoring target and sends the video signal to the input terminal of the video switching unit (VSW) 12. At this time, the video switching unit (VSW) 12 is connected to the line abnormality detection unit (DR).
-DET) 16 when the abnormality detection signal is not output,
The video signal input from the imaging unit (VC) 11 is transmitted to the first video transmission end (a), and the line abnormality detection unit (DR-DE)
When the abnormality detection signal is output from T) 16, the video signal input from the imaging unit (VC) 11 is transmitted to the second video transmission terminal (b).

Therefore, when there is no line abnormality in the dedicated transmission line 30, the video signal obtained by the imaging unit (VC) 11 is output from the first video transmission terminal (a) of the video switching unit (VSW) 12.

In a normal state in which no line abnormality has occurred, the radio transmission signal transmission unit (TX) 18 does not perform a transmission operation, and the radio transmission signal transmission unit (TX) 18 is in a low power consumption state. Or, the power is off. More specifically, the power transmission circuit (TX) 18 provided in the wireless transmission signal transmission unit (TX) 18 performs power saving control such as output suppression or power cut on a power amplifier circuit having a large power consumption, and performs wireless transmission signal transmission. The transmission unit (TX) 18 is set to the operation stop state or the operation pause state.

In this case, the video switching unit (VSW) 12
The video signal output from the first video transmission end (a)
After being converted into an optical signal via the / O conversion unit 13, the signal is synthesized by an optical multiplexing / demultiplexing unit (OBF) 14 and sent out onto the dedicated transmission line 30 as an optical signal of wavelength f1.

Further, the optical multiplexing / demultiplexing unit (OBF) 14 is provided with an optical signal of wavelength f2 (converted into an optical signal) transmitted from the central monitoring device (CS) 20 provided at the monitoring center onto the dedicated transmission line 30. Input the signal for line check)
A line abnormality detector (DR-DE) via the O / E converter 15
T) 16.

The line abnormality detector (DR-DET) 16
Dedicated transmission path 30 based on the input line check signal
It is determined whether or not the upper line is functioning normally, and if a line abnormality is detected, the detection signal activates the wireless transmission signal transmitter (TX) 18 to set the desired high-frequency power output state. The video switching unit (VSW) 12 is controlled to be switched, and the video signal input from the imaging unit (VC) 11 is transmitted to the second transmission terminal (b) instead of the first transmission terminal (a).

At this time, after the video signal output from the second video transmitting end (b) of the video switching unit (VSW) 12 is compressed by encoding in the video encoding unit (ENC) 17, the radio signal is transmitted. The signal is converted into a high-frequency signal by a carrier of a predetermined frequency in a transmission signal transmission unit (TX) 18 and transmitted and output as a radio transmission signal from an antenna (antenna).

On the other hand, in the central monitoring apparatus (CS) 20 provided in the monitoring center, the optical signal of the wavelength f1 transmitted from the monitoring terminal (TM) 10 is transmitted via the dedicated transmission line 30 to the optical multiplexing / demultiplexing unit (CS). OBF) after being input to 21 and demultiplexed,
The video signal is converted into an electric signal by the / E conversion unit 22, and the video signal is transmitted to the monitor display unit (MON) 23 via the video switcher (VSW) 29, and is output on a display screen in a predetermined display form. For example, a plurality of monitoring terminals (TM) 1
Each video received from 0, 10,... Is displayed simultaneously on a multi-screen. Or a plurality of monitoring terminals (TM) 10, 10,...
Each video received from is switched and displayed on a fixed time basis.

After the line check signal generated from the line check signal generator 24 is converted into an optical signal by the E / O converter 25, the signal is combined by the optical multiplexing / demultiplexing unit (OBF) 21 to obtain a wavelength. The signal is transmitted to the dedicated transmission line 30 as an optical signal of f2.

When a radio transmission signal transmitted from each of the monitoring terminals (TM) 10, 10,... Is received by the radio transmission signal receiving section (RX) 26 at the time of a line abnormality, the radio transmission signal Is demodulated as a coded video signal, and further decoded by a video decoding unit (DEC) 27. The decoded video signal is sent to a monitor display unit (MON) 28 via a video switcher (VSW) 29 to display a predetermined display. It is displayed on the display screen in the form. The video switcher (VS)
The video signal selection means W) 29 determines the state of the wireless transmission from the monitoring terminal (TM) 10 by monitoring the reception signal level of the wireless transmission signal receiver (RX) 26, for example, and determines the switching control signal (SC) according to the determination. ) Means for automatic switching, or a switching control signal (S
Any switching means such as a means for switching according to C) may be used.

In the system configuration of the above-described embodiment, each monitoring terminal (TM) 10, 10,... Transmits a video signal using a carrier in the same frequency band, or each monitoring terminal (TM) Terminal (TM) 10,
.. May be any system configuration for transmitting video signals using carrier waves in different frequency bands. When each monitoring terminal (TM) 10, 10,... Transmits a video signal using a carrier in the same frequency band, a central monitoring device (CS) 20 provided in a monitoring center has The monitoring terminal (TM) 10 that is transmitting can be specified by the identification information included in the received data. Also, in a system configuration in which each of the monitoring terminals (TM) 10, 10,... Transmits a video signal using a carrier in a different frequency band, the central monitoring device (CS) 20
In this case, the monitoring terminal (TM) 10 during transmission can be specified by a configuration in which a plurality of reception devices having different reception frequencies are provided or a configuration in which the reception frequency is sequentially varied to search for a transmission terminal.

By providing the automatic switching function of the video transmission as described above, the video transmission can be continued even when a transmission line abnormality such as a cable disconnection due to an earthquake or construction occurs, and particularly in a disaster. Therefore, a system failure in which video transmission is interrupted can be eliminated. Further, since the activation of the wireless transmission signal transmission unit (TX) 18 is controlled only when a line abnormality occurs in the dedicated transmission line 30, waste of power consumption in a normal line state can be eliminated. Since the video transmitted via the MFP and the video transmitted wirelessly are displayed on the common monitor display unit (MON) 23, a system having an automatic video transmission switching function can be configured inexpensively and simply.

FIGS. 3 and 4 show application examples of the video transmission device and the monitoring system according to the above-described embodiment of the present invention.

FIG. 3 is a block diagram showing a system configuration in which video transmission apparatuses according to the embodiment of the present invention are connected by an optical network 300. In the figure, 100 corresponds to the monitoring terminal (TM) 10 in the above embodiment. Video transmission device (or camera device) having video transmission switching control function
Is a monitoring device having a video transmission switching control function corresponding to the central monitoring device (CS) 20 provided in the monitoring center in the above embodiment. Reference numeral 300 denotes each of the video transmission devices (TM) 100, 100,... And the monitoring device (CS) 200.
Is a communication network that is the main video transmission path between
Here, a ring-shaped optical network is shown as an example, but an optical network other than a ring configuration or a network configuration using a metal cable may be used.

An OC is a transmission control device for connecting the above devices to a network.

In the video transmission device (TM) 100, V
C is an ITV camera or other video equipment corresponding to the imaging unit (VC) 11 shown in FIG. 1 or FIG. 2, VSW is a video switching unit also corresponding to the video switching unit (VSW) 12, EN
C is a video encoder corresponding to the video encoder (ENC) 17, and TX is a wireless transmission signal transmitter (TX) 1
8 is a transmission unit. Also, the monitoring device (CS) 2
In RX, RX is a receiving unit corresponding to the radio transmission signal receiving unit (RX) 26 shown in FIG. 1 or 2, DEC is a video decoding unit also corresponding to the video decoding unit (DEC) 27,
VSW is a video switcher corresponding to the video switcher (VSW) 29 shown in FIG. 2, and MON is a monitor display unit corresponding to the monitor display unit (MON) 23 shown in FIG.

In the system shown in FIG. 3, each of the video transmission apparatuses (TM) 100, 100,..., When a line abnormality occurs in the optical network 300 serving as a main video transmission path and a video transmission failure occurs. A transmission unit (TX) for transmitting a video signal using a carrier in the same frequency band, or a video transmission device (TM) 10
.. May be any system configuration in which a transmission unit (TX) for transmitting a video signal using a carrier wave in a different frequency band is provided.

Each video transmission device (TM) 100, 100,
, A transmission unit (TX) for transmitting a video signal using a carrier in the same frequency band is provided in the monitoring device (CS) 200 or in the transmission control device (VC) connected to the device. By providing a discriminating means for specifying the monitoring terminal (TM) 100 that is transmitting based on the identification information included in the received data, it is possible to identify which transmission device (TM) the video is transmitted from and display it on the monitor. . Also, in the case of a system configuration in which each of the video transmission devices (TM) 100, 100,... Has a transmission unit (TX) for transmitting a video signal using a carrier in a different frequency band, the monitoring device (CS) 200 By providing the receiving unit (RX) with a function of sequentially changing the signal frequency and searching for the transmitting terminal, the monitoring terminal (TM) 10 transmitting by the single receiving unit can be specified and displayed on the monitor. .

FIG. 4 is a diagram showing various application examples of the video transmission device and the system according to the embodiment of the present invention. Here, an example in which the invention is applied to tunnel monitoring, monitoring of a long bridge, and the like is shown. In the figure, reference numeral 100 denotes the monitoring terminal (T
M) A camera device corresponding to 10, and 200 is a central monitoring device (C) provided in the monitoring center in the above embodiment.
S) A monitoring device corresponding to 20, and an optical fiber cable 400 serving as a main video transmission line of each of the above devices. RX is a receiving unit corresponding to the radio transmission signal receiving unit (RX) 26 shown in FIG. 1 or 2, and DEC is a video decoding unit (DEC)
A video decoding unit and VSW corresponding to 27 are video switchers corresponding to a video switcher (VSW) 29 shown in FIG.

In the above-described embodiment, the dedicated transmission line 30 is constituted by an optical fiber cable, and the spare transmission means when the main line is abnormal is constituted by a wireless transmission means.
The device of the present invention can be applied to a system configuration using any combination of a transmission line using an optical fiber cable, a transmission line using a metal cable such as ISDN, a wireless transmission line, and the like.

[0067]

As described above in detail, according to the present invention, in a system for transmitting video information using a transmission line using an optical fiber cable, a metal cable, or the like, an earthquake,
It is possible to provide a video transmission device that can continue video transmission even when a transmission path abnormality such as cable disconnection due to construction or the like occurs.

According to the present invention, a monitoring system for transmitting video information obtained by a plurality of monitoring terminals having a monitoring camera to a central monitoring device via an optical fiber cable and remotely monitoring by the monitoring device. Therefore, it is possible to provide a surveillance system capable of continuing the video transmission and continuing the intended surveillance work even when a transmission path abnormality such as a cable disconnection due to an earthquake or construction occurs.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing an application example of the present invention.

FIG. 4 is a block diagram showing an application example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Monitoring terminal (TM) 11 ... Image pick-up part (VC) 12 ... Video switching part (VSW) 13 ... E / O conversion part 14 ... Optical multiplexing / demultiplexing part (OBF) 15 ... O / E conversion part 16 ... Line abnormality detection Unit (DR-DET) 17 Video encoding unit (ENC) 18 Radio transmission signal transmitting unit (TX) 20 Central monitoring device (CS) provided at monitoring center 21 Optical multiplexing / demultiplexing unit (OBF) 22 O / E conversion unit 23: monitor display unit (MON), 24: signal generator for line check 25 ... E / O conversion unit 26 ... radio transmission signal reception unit (RX) 27 ... video decoding unit (DEC) 28 ... Monitor display (MON) 29 Video switcher (VSW)

Continued on front page F-term (reference) AA02 BB08 CC12 CC13 CC14 DD02 EE06 FF01 FF11 5K059 AA01 AA04 AA11 BB02

Claims (6)

[Claims] A main transmission line for transmitting a video signal to a predetermined point; an encoding unit for encoding the video signal; a line abnormality detection unit for detecting a line abnormality on the main transmission line; A video transmitting the video signal to the main transmission path when the line abnormality is not detected by the line abnormality detecting means, and transmitting the video signal to the encoding means when the line abnormality is detected by the line abnormality detecting means. A video transmission device comprising: a switching control unit; and a spare transmission unit that transmits a video signal encoded by the encoding unit to the point. 2. A monitoring camera, a first transmission unit for transmitting a video signal obtained from the camera to a predetermined point, and a line abnormality detection unit for detecting a line abnormality of the first transmission unit And a second transmission unit that encodes a video signal obtained from the camera when the line abnormality is detected by the line abnormality detection unit and transmits the encoded signal to the predetermined point. Surveillance camera device. 3. A surveillance camera, an optical transmission line for converting a video signal obtained from the camera into an optical signal and transmitting the optical signal to a predetermined point, and encoding for coding a video signal obtained from the camera. Processing means, a line abnormality detecting means for detecting a line abnormality of the optical transmission line, and when the line abnormality is detected by the line abnormality detecting means, a video signal encoded by the encoding processing means is converted to a high frequency of a predetermined frequency. A surveillance camera device comprising: a wireless transmission unit that modulates a signal and wirelessly transmits the signal to the predetermined point. 4. In a surveillance system for transmitting image information obtained by a plurality of surveillance terminals having a surveillance camera to a central surveillance device via an optical cable and remotely monitoring by the surveillance device, Means for detecting a line abnormality on the transmission line by the optical cable, and means for encoding video information obtained by the camera when a line abnormality is detected by the unit,
Means for wirelessly transmitting the video information encoded by the means using a carrier wave of a predetermined frequency, wherein the monitoring device receives the video information transmitted from the monitoring terminal, and the video received by the means. A monitoring system comprising: means for decoding information; and means for displaying video information decoded by the means on a monitor. 5. The monitoring system according to claim 4, wherein each of said monitoring terminals uses a carrier wave in the same frequency band. 6. The monitoring system according to claim 4, wherein said means for wirelessly transmitting uses a carrier of a different frequency band for each monitoring terminal.